CVE-2026-25536

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 96% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.1Exploit: NoneExposed: 0

A fix is available — apply it.

MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. From version 1.10.0 to 1.25.3, cross-client response data leak when a single McpServer/Server and transport instance is reused across multiple client connections, most commonly in stateless StreamableHTTPServerTransport deployments. This issue has been patched in version 1.26.0.

CVSS v3
7.1
EG Score
7.1(medium)
EPSS
18.4%
KEV
Not listed

Published

February 4, 2026

Last Modified

July 15, 2026

Advisory Details (7)

Auto-updated Jul 15, 2026
Patch available. Sources: github, redhat.
redhat Patch Available
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25536.json
redhat

2436937 – (CVE-2026-25536) CVE-2026-25536 @modelcontextprotocol/sdk: @modelcontextprotocol/sdk cross-client data leak

https://bugzilla.redhat.com/show_bug.cgi?id=2436937
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-25536
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:3960
github Patch Available

Sharing server/transport instances can leak cross-client response data · Advisory · modelcontextprotocol/typescript-sdk · GitHub

https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7
generic

How to use MCP client in a multi-user application? · Issue #243 · modelcontextprotocol/typescript-sdk · GitHub

https://github.com/modelcontextprotocol/typescript-sdk/issues/243
generic

Multiple clients to the same SSE connection? · Issue #204 · modelcontextprotocol/typescript-sdk · GitHub

https://github.com/modelcontextprotocol/typescript-sdk/issues/204

Vendor Advisories for CVE-2026-25536(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatansible-automation-platform-tech-preview/mcp-server-rhel9:sha256:40a0e5a857cd2ee1e083849eb5413a3acbc681c28816c4270badeceec5ae76512026-03-06redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
@modelcontextprotocol/sdk—1.26.0—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 51× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 02:00 UTCEPSS rescore
  4. 2026-07-15 02:00 UTCEPSS rescore
  5. 2026-07-13 22:30 UTCEPSS rescore
  6. 2026-07-13 08:07 UTCOSV refresh
  7. 2026-07-13 06:13 UTCEPSS rescore
  8. 2026-07-13 06:13 UTCEPSS rescore
  9. 2026-07-12 05:46 UTCEPSS rescore
  10. 2026-07-12 05:46 UTCEPSS rescore
  11. 2026-07-11 08:27 UTCEPSS rescore
  12. 2026-07-09 19:10 UTCEPSS rescore
  13. 2026-07-08 15:15 UTCEPSS rescore
  14. 2026-07-08 15:15 UTCEPSS rescore
  15. 2026-07-07 13:46 UTCEPSS rescore
  16. 2026-07-06 16:27 UTCEPSS rescore
  17. 2026-07-06 16:27 UTCEPSS rescore
  18. 2026-07-06 02:23 UTCEPSS rescore
  19. 2026-07-06 02:23 UTCEPSS rescore
  20. 2026-07-05 02:30 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-04 06:31 UTCEPSS rescore
  23. 2026-07-01 15:06 UTCEPSS rescore
  24. 2026-07-01 15:06 UTCEPSS rescore
  25. 2026-06-30 23:22 UTCEPSS rescore
Show 62 more
  1. 2026-06-30 23:22 UTCEPSS rescore
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-28 14:07 UTCEPSS rescore
  4. 2026-06-28 14:07 UTCEPSS rescore
  5. 2026-06-28 04:56 UTCEPSS rescore
  6. 2026-06-28 04:56 UTCEPSS rescore
  7. 2026-06-27 03:08 UTCEPSS rescore
  8. 2026-06-25 13:49 UTCEPSS rescore
  9. 2026-06-25 13:49 UTCEPSS rescore
  10. 2026-06-24 22:01 UTCOSV refresh
  11. 2026-06-24 14:05 UTCEPSS rescore
  12. 2026-06-24 14:05 UTCEPSS rescore
  13. 2026-06-23 21:33 UTCEPSS rescore
  14. 2026-06-23 21:32 UTCEPSS rescore
  15. 2026-06-22 14:25 UTCEPSS rescore
  16. 2026-06-22 14:25 UTCEPSS rescore
  17. 2026-06-21 14:56 UTCEPSS rescore
  18. 2026-06-21 14:56 UTCEPSS rescore
  19. 2026-06-21 01:59 UTCEPSS rescore
  20. 2026-06-21 01:59 UTCEPSS rescore
  21. 2026-06-19 19:25 UTCEPSS rescore
  22. 2026-06-19 19:25 UTCEPSS rescore
  23. 2026-06-18 17:52 UTCEPSS rescore
  24. 2026-06-17 17:53 UTCEPSS rescore
  25. 2026-06-17 17:53 UTCEPSS rescore
  26. 2026-06-16 17:52 UTCEPSS rescore
  27. 2026-06-15 17:48 UTCEPSS rescore
  28. 2026-06-14 23:18 UTCEPSS rescore
  29. 2026-06-13 23:00 UTCEPSS rescore
  30. 2026-06-12 23:12 UTCEPSS rescore
  31. 2026-06-12 23:12 UTCEPSS rescore
  32. 2026-06-11 14:00 UTCEPSS rescore
  33. 2026-06-10 22:18 UTCEPSS rescore
  34. 2026-06-10 22:18 UTCEPSS rescore
  35. 2026-06-10 13:22 UTCEPSS rescore
  36. 2026-06-08 14:17 UTCEPSS rescore
  37. 2026-06-08 14:17 UTCEPSS rescore
  38. 2026-06-07 21:27 UTCEG score recompute
  39. 2026-06-07 21:27 UTCVendor advisory
  40. 2026-06-07 15:25 UTCEPSS rescore
  41. 2026-06-07 15:25 UTCEPSS rescore
  42. 2026-06-07 15:25 UTCEPSS rescore
  43. 2026-06-06 13:47 UTCEPSS rescore
  44. 2026-06-06 13:47 UTCEPSS rescore
  45. 2026-06-05 22:47 UTCEPSS rescore
  46. 2026-06-05 22:47 UTCEPSS rescore
  47. 2026-06-05 06:10 UTCEPSS rescore
  48. 2026-06-05 06:10 UTCEPSS rescore
  49. 2026-06-04 13:12 UTCEPSS rescore
  50. 2026-06-04 13:12 UTCEPSS rescore
  51. 2026-06-02 20:13 UTCEPSS rescore
  52. 2026-06-02 20:13 UTCEPSS rescore
  53. 2026-06-01 13:51 UTCEPSS rescore
  54. 2026-06-01 13:51 UTCEPSS rescore
  55. 2026-05-31 22:30 UTCEPSS rescore
  56. 2026-05-31 22:30 UTCEPSS rescore
  57. 2026-05-31 00:16 UTCEPSS rescore
  58. 2026-05-31 00:16 UTCEPSS rescore
  59. 2026-05-29 14:35 UTCEG score recompute
  60. 2026-05-29 14:35 UTCVendor advisory
  61. 2026-05-29 13:44 UTCEPSS rescore
  62. 2026-05-29 13:44 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-25536?
CVE-2026-25536 is a high vulnerability published on February 4, 2026. MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. From version 1.10.0 to 1.25.3, cross-client response data leak when a single McpServer/Server and transport instance is reused across multiple client connections, most commonly in stateless…
When was CVE-2026-25536 disclosed?
CVE-2026-25536 was first published in the National Vulnerability Database on February 4, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-25536 actively exploited?
CVE-2026-25536 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 18.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-25536?
CVE-2026-25536 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-25536?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-25536, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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